Continuum and atomistic modeling of lipid membranes : biophysics of hair cell mechanotransduction
Abstract/Contents
- Abstract
- A lipid bilayer membrane is not just a simple inert barrier of cells, but a dynamic structure which plays a crucial role in cell functioning. A force conveying role of the lipid membrane for the mechanosensitive ion channels is now an accepted phenomenon across various mechanoreceptors. However, such a mechanism has not been established for mechanotransduction in the hair bundle of the auditory sensory hair cell. A major goal of this theoretical study is to investigate the role of the lipid membrane in the hair bundle mechanotransduction in the auditory system, especially in generating the nonlinear bundle force vs. displacement measurements -- one of the main features of auditory mechanotransduction. To this end we developed a hair bundle model which reproduces the lipid membrane tented deformation in the stereocilia. To analyze the membrane deformation, the conventional Helfrich theory for the lipid membrane is modified and solved by a novel numerical method using Fourier series. Our hair bundle model, incorporating membrane elasticity with bundle rigid body kinematics and lipid flow components, reproduces nonlinear bundle force measurements and in so doing potentially elucidates aspects of hair cell transduction for which the physical basis has been elusive for three decades. The nonlinear force vs. displacement calculation of the tented membrane, the central goal of this analysis, is further supported by the nonlinear finite element (FE) formulation. This Galerkin finite element method uses the B-spline basis function and Newton's method to solve the nonlinear equation system. By repeating the tenting problem with the finite element method, the consistency of the force vs. displacement calculation compared to our previous approach is demonstrated. The validity of the continuum analysis is also investigated though atomistic modeling of the lipid membrane. The coarse-grained molecular dynamics simulation of the tented lipid membrane is performed. Generating similar nonlinearity validates our previous continuum analysis of the membrane based on the Helfrich theory and supports the role of the lipid membrane in generating nonlinear hair bundle mechanics.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2013 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Kim, Jichul |
|---|---|
| Associated with | Stanford University, Department of Mechanical Engineering. |
| Primary advisor | Pinsky, P |
| Primary advisor | Steele, C. R. (Charles R.) |
| Thesis advisor | Pinsky, P |
| Thesis advisor | Steele, C. R. (Charles R.) |
| Thesis advisor | Cai, Wei, 1977- |
| Advisor | Cai, Wei, 1977- |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Jichul Kim. |
|---|---|
| Note | Submitted to the Department of Mechanical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2013. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2013 by Jichul Kim
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